1. Field of the Invention
The present invention relates to an apparatus for processing a signal in a digital television, and more particularly, to an apparatus for adaptively processing an externally-input video signal in a digital television, in which a signal processing route is controlled to automatically determine the type of a video signal, which is input to an external input terminal, and to adaptively process the video signal regardless of whether the signal is an interlaced scanned video signal or a progressive scanned video signal.
2. Description of the Related Art
In general, a progressive scan converting method is applied to a digital television to improve image quality. In the progressive scan converting method, the vertical frequency of a video signal is not changed, and an interpolated line is inserted between each of the horizontal lines of a field signal using a motion vector, and then the horizontal frequency of the video signal is doubled.
A signal in which the horizontal frequency of the video signal is doubled by the progressive scan converting method is referred to as a video signal having a horizontal sweep rate of 2H, and a conventional interlaced scanning video signal, which is not converted into a progressive scanning video signal, is referred to as a video signal having a horizontal sweep rate of 1H. The externally input 1H video signal is processed and output in the digital television by the above method.
According to recent developments in the technology, however, in a signal processing apparatus such as a DVDP (digital video disk player), the 1H video signal and/or the 2H video signal are/is output in accordance with the products specification. Accordingly, it has been determined that there is a problem in that the video signal input in the form of the 2H video signal cannot be processed in the digital television using the above converting method.
To solve the above problem, it is an object of the present invention to provide an apparatus for adaptively processing an externally-input video signal in a digital television, in which the standard of a video signal input from a video input terminal of the digital television is determined, and a signal processing block is controlled to automatically adapt to a video signal having a 1H sweep rate or a video signal having a 2H sweep rate according to the standard of the determined video signal.
Accordingly, to achieve the above object, there is provided an apparatus for adaptively processing an externally input video signal in a digital television, for processing a broadcasting signal, which is received and decoded via an antenna, and a video signal which is input to an external input terminal. The apparatus includes a first switching unit for switching input terminals and selectively outputting a received decoded broadcasting signal or the video signal received via the external input terminal by a first switching control signal; a synchronizing signal detecting unit for receiving the video signal output from the first switching unit and detecting a synchronizing signal; a control unit for generating the first switching control signal to select an input signal which corresponds to a video input mode selected by a user, determining the frequency of the synchronizing signal detected and output from the synchronizing signal detecting unit, and generating a second switching control signal to switch the input signal to an output terminal which corresponds to the standard of the video signal output from the first switching unit; a second switching unit for receiving the video signal output from the first switching unit, outputting a video signal having a 1H horizontal sweep rate to a first output terminal and a video signal having a 2H horizontal sweep rate to a second output terminal by the second switching control signal; a progressive scan converting unit for receiving the video signal having a 1H horizontal sweep rate of the first output terminal of the second switching unit, converting the video signal having a 1H horizontal sweep rate into a video signal having a 2H horizontal sweep rate, the horizontal frequency of which is doubled by line interpolation; and a matrix processing unit for receiving a signal output from the second output terminal of the second switching unit or an output signal of the progressive scan converting unit for converting the received signal into an R, G, B signal.